When a character is injured by a contaminated attack, touches an item smeared with diseased matter, or consumes disease-tainted food or drink, he must make an immediate Fortitude saving throw. If he succeeds, the disease has no effect—his immune system fought off the infection. If he fails, he takes damage after an incubation period. Once per day afterward, he must make a successful Fortitude saving throw to avoid repeated damage. Two successful saving throws in a row indicate that he has fought off the disease and recovers, taking no more damage.

These Fortitude saving throws can be rolled secretly so that the player doesn’t know whether the disease has taken hold.
Disease Descriptions

Diseases have various symptoms and are spread through a number of vectors. The characteristics of several typical diseases are summarized below.

Diseases whose names are printed in italic in the table are supernatural in nature. The others are extraordinary.

Infection
The disease’s method of delivery—ingested, inhaled, via injury, or contact. Keep in mind that some injury diseases may be transmitted by as small an injury as a flea bite and that most inhaled diseases can also be ingested (and vice versa).

DC
The Difficulty Class for the Fortitude saving throws to prevent infection, or (if the character has been infected), to prevent each instance of repeated damage, and to recover from the disease.

Incubation Period
The time before damage begins.

Damage
The ability damage the character takes after incubation and each day afterward.

Disease

Infection

DC

Incubation

Damage

Blinding sickness

Ingested

16

1d3 days

1d4 Str1

Cackle fever

Inhaled

16

1 day

1d6 Wis

Demon fever

Injury

18

1 day

1d6 Con2

Devil chills3

Injury

14

1d4 days

1d4 Str

Filth fever

Injury

12

1d3 days

1d3 Dex, 1d3 Con

Mindfire

Inhaled

12

1 day

1d4 Int

Mummy rot4

Contact

20

1 day

1d6 Con

Red ache

Injury

15

1d3 days

1d6 Str

Shakes

Contact

13

1 day

1d8 Dex

Slimy doom

Contact

14

1 day

1d4 Con2

1. Each time the victim takes 2 or more damage from the disease, he must make another Fortitude save or be permanently blinded.
2. When damaged, character must succeed on another saving throw or 1 point of damage is permanent drain instead.
3. The victim must make three successful Fortitude saving throws in a row to recover from devil chills.
4. Successful saves do not allow the character to recover. Only magical healing can save the character.

Types of Diseases
Typical diseases include the following:Blinding Sickness
Spread in tainted water.

Cackle Fever
Symptoms include high fever, disorientation, and frequent bouts of hideous laughter. Also known as “the shrieks.”

Demon Fever
Night hags spread it. Can cause permanent ability drain.

Devil Chills
Barbazu and pit fiends spread it. It takes three, not two, successful saves in a row to recover from devil chills.

Healing A Disease
Use of the Heal skill can help a diseased character. Every time a diseased character makes a saving throw against disease effects, the healer makes a check. The diseased character can use the healer’s result in place of his saving throw if the Heal check result is higher. The diseased character must be in the healer’s care and must have spent the previous 8 hours resting.

Characters recover points lost to ability score damage at a rate of 1 per day per ability damaged, and this rule applies even while a disease is in progress. That means that a character with a minor disease might be able to withstand it without accumulating any damage.